ignoreErrors for Raise (#3100)

Co-authored-by: Simon Vergauwen <[email protected]>

Author: serras

arrow-libs/core/arrow-core/api/arrow-core.api

@@ -3333,6 +3333,30 @@ public final class arrow/core/raise/DefaultRaise : arrow/core/raise/Raise {
 public abstract interface annotation class arrow/core/raise/ExperimentalTraceApi : java/lang/annotation/Annotation {
 }
 
+public final class arrow/core/raise/IgnoreErrorsRaise : arrow/core/raise/Raise {
+	public fun <init> (Larrow/core/raise/Raise;Lkotlin/jvm/functions/Function0;)V
+	public fun attempt (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun bind (Larrow/core/Either;)Ljava/lang/Object;
+	public final fun bind (Larrow/core/Option;)Ljava/lang/Object;
+	public fun bind (Larrow/core/Validated;)Ljava/lang/Object;
+	public fun bind (Larrow/core/continuations/EagerEffect;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun bind (Larrow/core/continuations/Effect;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public final fun bind (Ljava/lang/Object;)Ljava/lang/Object;
+	public fun bind (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
+	public fun bind (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun bindAll (Larrow/core/NonEmptyList;)Larrow/core/NonEmptyList;
+	public fun bindAll (Ljava/lang/Iterable;)Ljava/util/List;
+	public fun bindAll (Ljava/util/Map;)Ljava/util/Map;
+	public fun bindAll-1TN0_VU (Ljava/util/Set;)Ljava/util/Set;
+	public fun catch (Larrow/core/continuations/Effect;Lkotlin/jvm/functions/Function3;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public final fun ensure (Z)V
+	public final fun ensureNotNull (Ljava/lang/Object;)Ljava/lang/Object;
+	public fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
+	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun raise (Ljava/lang/Object;)Ljava/lang/Void;
+	public fun shift (Ljava/lang/Object;)Ljava/lang/Object;
+}
+
 public final class arrow/core/raise/IorRaise : arrow/core/raise/Raise {
 	public fun <init> (Lkotlin/jvm/functions/Function2;Ljava/util/concurrent/atomic/AtomicReference;Larrow/core/raise/Raise;)V
 	public fun attempt (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -3381,6 +3405,7 @@ public final class arrow/core/raise/NullableRaise : arrow/core/raise/Raise {
 	public fun catch (Larrow/core/continuations/Effect;Lkotlin/jvm/functions/Function3;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public final fun ensure (Z)V
 	public final fun ensureNotNull (Ljava/lang/Object;)Ljava/lang/Object;
+	public final fun ignoreErrors (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public synthetic fun raise (Ljava/lang/Object;)Ljava/lang/Void;
@@ -3411,6 +3436,7 @@ public final class arrow/core/raise/OptionRaise : arrow/core/raise/Raise {
 	public fun catch (Larrow/core/continuations/Effect;Lkotlin/jvm/functions/Function3;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public final fun ensure (Z)V
 	public final fun ensureNotNull (Ljava/lang/Object;)Ljava/lang/Object;
+	public final fun ignoreErrors (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun raise (Larrow/core/None;)Ljava/lang/Void;

arrow-libs/core/arrow-core/src/commonMain/kotlin/arrow/core/raise/Builders.kt

@@ -94,6 +94,37 @@ public inline fun <Error, A> ior(noinline combineError: (Error, Error) -> Error,
   )
 }
 
+/**
+ * Implementation of [Raise] used by `ignoreErrors`.
+ * You should never use this directly.
+ */
+public class IgnoreErrorsRaise<N>(
+  private val raise: Raise<N>,
+  private val error: () -> N
+) : Raise<Any?> {
+  @RaiseDSL
+  override fun raise(r: Any?): Nothing =
+    raise.raise(error())
+
+  @RaiseDSL
+  public fun ensure(value: Boolean): Unit = ensure(value) { null }
+
+  @RaiseDSL
+  public fun <A> Option<A>.bind(): A = getOrElse { raise(null) }
+
+  @RaiseDSL
+  public fun <A> A?.bind(): A {
+    contract { returns() implies (this@bind != null) }
+    return this ?: raise(null)
+  }
+
+  @RaiseDSL
+  public fun <A> ensureNotNull(value: A?): A {
+    contract { returns() implies (value != null) }
+    return ensureNotNull(value) { null }
+  }
+}
+
 public typealias Null = Nothing?
 
 /**
@@ -136,6 +167,15 @@ public class NullableRaise(private val raise: Raise<Null>) : Raise<Null> by rais
     null -> recover()
     else -> nullable
   }
+
+  /**
+   * Introduces a scope where you can [bind] errors of any type,
+   * but no information is saved in the [raise] case.
+   */
+  @RaiseDSL
+  public inline fun <A> ignoreErrors(
+    @BuilderInference block: IgnoreErrorsRaise<Null>.() -> A,
+  ): A = block(IgnoreErrorsRaise(this) { null })
 }
 
 /**
@@ -219,6 +259,15 @@ public class OptionRaise(private val raise: Raise<None>) : Raise<None> by raise
     is None -> recover()
     is Some<A> -> option.value
   }
+
+  /**
+   * Introduces a scope where you can [bind] errors of any type,
+   * but no information is saved in the [raise] case.
+   */
+  @RaiseDSL
+  public inline fun <A> ignoreErrors(
+    @BuilderInference block: IgnoreErrorsRaise<None>.() -> A,
+  ): A = block(IgnoreErrorsRaise(this) { None })
 }
 
 /**

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/raise/NullableSpec.kt

@@ -69,6 +69,22 @@ class NullableSpec : StringSpec({
     } shouldBe "1"
   }
 
+  "binding either in nullable" {
+    nullable {
+      val number = Either.Right("s".length)
+      val string = number.map(Int::toString).bind()
+      string
+    } shouldBe "1"
+  }
+
+  "binding either in nullable, ignore errors" {
+    nullable {
+      val number = Either.Right("s".length) as Either<Boolean, Int>
+      val string = ignoreErrors { number.map(Int::toString).bind() }
+      string
+    } shouldBe "1"
+  }
+
   "short circuit option" {
     nullable<Int> {
       val number = Some("s".length)